The 4 Spinal-Eshus are centered where I illustrate them, but can be larger in size, and somewhat link with each other along the spine ending in connections up and down to infinity (as illustrated). They are not really red, but (as all Eshus do) have an affinity with red and black.
In some ways they are part of the Brains system (for example they provide some of the power which the Brains use as well as effecting the Brains in other ways), and in some ways a separate system. For more info on Eshu see below.
Many humans have one or more of the Spinal-Eshus in a Reversed condition, and/or the flow through them in a weakened condition (due to barriers, breaks, holes etc.). This (along with head-Brian dominance) will usually result in energy being trapped in the head instead of flowing down the front of the body, and this (plus compressions of certain spaces) usually results in a head-ache, and/or stiff neck and shoulders.
The Spinal-Eshu system should have an aura around it to protect it from unwanted influences, but this is in poor condition for many humans.